The true cause of Britain's worst peace-time industrial accident, which killed 28 people, is to be revealed by the Health and Safety Executive after 26 years of campaigning by awhistle-blowing scientist sacked from the original inquiry.
In 1974, a huge explosion ripped apart a chemical plant in Flixborough, on the banks of the Trent in Lincolnshire. As well as the large number who died, 53 people were injured and the small town in the area was wrecked. Blast waves were felt four miles away in Scunthorpe.
Ralph King, a scientist aged 81, has devoted his life since the disaster to discovering what happened that day, saying the original inquiry was wrong to blame a simple mechanical failure. "I realised that what we were really there for was to come up with a cause which would not embarrass the company," he said yesterday, at his home in Ewell, Surrey.
Mr King, an eminent industrial chemist and the author of several definitive textbooks on industrial safety, is calling for a new investigation into the catastrophe. "It is now time for the court of inquiry to be reopened so that all the facts can be properly and fully established."
Mr King's MP, Sir Archie Hamilton, the respected technical journal Chemical Engineer, and a number of leading scientists are supporting Mr King's calls for a reinvestigation. Russ Swan, the editor of the Chemical Engineer, says, "The original inquiry looks more and more like a cover-up."
Sir Archie said: "I have been pressing for a new inquiry with Michael Meacher [the Environment minister], as new evidence now seems to have been produced. This was a serious disaster and if the inquiry was wrong about what caused it, that's not very clever. We should get to the bottom of it."
Because of his pressure, the Health and Safety Executive commissioned new research, which is believed to confirm that the disaster at the Nypro plant at Flixborough was the result of blundering ignorance rather than the simple mechanical failure blamed by the official court of inquiry.
Experiments carried out at the executive's laboratory in Buxton, Derbyshire, follow repeated claims by Mr King that the board of inquiry's simplistic explanation for the massive explosion was a whitewash to cover up incompetence at the Flixborough plant.
Mr King was part of the original team that was set up to investigate the disaster. "They wanted a cover-up and I was not prepared to do that and when I said that I wanted to investigate other matters than a mere mechanical failure, I was removed from the investigation." he said.
The plant at Flixborough produced the raw materials for nylon. The disaster happened during the processing of cyclohexane - a highly inflammable component liquid - when a temporary bypass assembly linking two of the plant's six reactors suddenly failed, causing some of the chemical to escape. The leak then ignited to cause the blast. Mr King argues that the rupture was caused by a massive build-up of pressure, which was triggered by a series of events that would not have been permitted to occur had the process been fully understood by Nypro's chemical engineers.
His theory is that the presence of water inside the reactors, and the simultaneous shutting down of crucial stirring equipment, caused the explosion. "In its simplest form it's a bit like throwing water on to a burning chip pan." Mr Swan said.
Mr King did not conceive his theory until after the inquiry closed. But for the past 25 years he and many other leading scientists who believe the "water theory" have pleaded in vain for the inquiry to be reopened. "We are now awaiting the publication of the Buxton work and if, as I believe, they confirm my findings, there will be absolutely no excuse not to reopen the Flixborough inquiry," he said. "The acknowledgement of the truth behind this affair is long overdue."
A spokesman for the safety executive said yesterday that its laboratory experiments would have to undergo peer review and would be published later this year. "We would not support the reopening of the original inquiry. Our view is that the underlying conclusion of the inquiry is not being challenged, only the events leading up to the failure," he said.